The Expansion Technology Research Of COMPASS User Communication Data

Beidouâ… is a satellite navigation and positioning system of independent research anddevelopment in China, which contains three functions of accurate positioning, shortmessage communication and precision timing. With the development of the system, theapplication of Beidou gradually integrated into many social fields. For example, thefunction of short message communication is widely applied in military, disaster relief,marine fisheries, transportation and other fields. Various applications based on Beidoucommunication message has been greatly extended, so the capacity of Beidoucommunication need to be improved for users.This paper studies to improve the data capacity of Beidou communication, and themain researching contents are as follows:(1) GPS and Beidou system are briefly introduced, and their characteristics anddifferent application are compared with each other. The application of Beidoucommunication is introduced. Based on the fact that Beidou short messagecommunication is in use, the idea is put forward for enlarging communication data bydata expansion in the user side.(2) The entropy of Chinese characters information is introduced. By comparingthe five kinds of entropy of speech information to the United Nations, it is pointed outthat the information of the Chinese characters is largest, and then it is not suitable forthe information management and transfer.(3) Several common compression algorithms are analyzed for applying to theBeidou short message communication. Based on the characteristics that currentcompression algorithms are mainly in the western language, the algorithm of combinedcompression is proposed with intelligent Chinese word segmentation and Lempel-Zivlossless compression. That is based on GB-2312coding, to build custom Chinesedictionary and retrieval. The technique of Lempel-Ziv lossless compression is used tocompress the code after intelligent Chinese word segmentation, then so as to realize theexpansion of communication data.(4) Through the compressed effect of Beidou communication data using Unitedalgorithm in practice, the feasibility and stability are verified.